In Situ Investigation of Layered Oxides with Mixed Structures for Sodium‐Ion Batteries. Issue 11 (15th May 2019)

• Record Type: Journal Article
• Authors: Keller, Marlou; Eisenmann, Tobias; Meira, Debora; Aquilanti, Giuliana; Buchholz, Daniel; Bresser, Dominic; Passerini, Stefano
• Is Part Of: Small methods. Volume 3:Issue 11(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-05-15
• Subjects: cathode materials -- cobalt‐free -- NaxMn0.5Ni0.3Fe0.1Mg0.1O2 -- sodium batteries -- XAS; Nanotechnology -- Methodology -- Periodicals; Nanotechnology -- Periodicals; Periodicals; 620.5028
• DOI: 10.1002/smtd.201900239
• Languages: English
• ISSNs: 2366-9608

Abstract

Abstract: Experimentalists and theoreticians commonly prefer single‐phase materials for their studies, since this allows for a direct correlation of the findings obtained and the compound studied. For the design of high‐performance materials for energy applications, however, mixtures of different phases frequently reveal an advanced set of desired properties. Recently, it has been shown that a combination of different phases, that is, P2/P3/O3‐ Na x Mn0.5 Ni0.3 Fe0.1 Mg0.1 O2, allows for higher capacities and enhanced cycling stability when employed as sodium‐on cathode compared to pure P2‐Na x Mn0.7 Ni0.1 Fe0.1 Mg0.1 O2 or O3‐type Na x Mn0.5 Ni0.3 Fe0.1 Mg0.1 O2 . Herein, the in‐depth comparative investigation of these three materials is presented via in situ X‐ray diffraction and X‐ray absorption spectroscopy coupled with electrochemical techniques to fully elucidate the origin of this superior performance. In fact, it appears that the redox activity or inactivity of the manganese cation plays a decisive role for the reversibility of the sodium‐ion uptake and release. Abstract : Coupling electrochemical characterization techniques with advanced synchrotron methods is fundamental for the in‐depth understanding of the processes and mechanisms occurring in electrode active materials. Herein, P2‐, O3‐, and P2/P3/O3‐type sodium‐ion cathodes are investigated via in situ X‐ray diffraction and absorption spectroscopy to unveil the origin of their different cycling stabilities.